Dry developable photoresist containing an epoxide, organosilicon and onium salt

ABSTRACT

A dry developable photoresist composition that contains in admixture a polymeric epoxide; a di- or polyfunctional organosilicon material; and an onium salt; and use thereof to produce an image.

DESCRIPTION

1. Technical Field

The present invention is concerned with compositions which are capableof being imaged upon exposure to actinic radiation. The compositions ofthe present invention, after exposure to actinic radiation andcrosslinking, are also resistant to oxygen-containing plasmas. Inaddition, the present invention is concerned with the use of thecompositions in lithography. For example, the compositions of thepresent invention are suitable for imaging on all optical lithographytools and for packaging applications, such as multi-layer ceramicpackaging devices.

2. Background Art

In the manufacture of patterned devices, such as semiconductor chips andchip carriers, the processes of etching different layers whichconstitute the finished product are among the most crucial stepsinvolved. One method widely employed in the etching process is tooverlay the surface to be etched with a suitable mask and then toimmerse the substrate and mask in a chemical solution which attacks thesubstrate to be etched while leaving the mask intact. These wet chemicalprocesses suffer from the difficulty of achieving well-defined edges onthe etched surfaces. This is due to the chemicals undercutting the maskand the formation of an isotropic image. In other words, conventionalchemical wet processes do not provide the selectivity of direction(anisotropy) considered necessary to achieve optimum dimensionalconsistent with current processing requirements.

Moreover, such wet etching processes are undesirable because of theenvironmental and safety concerns associated therewith. Often thesolvents suggested are toxic; thereby creating disposal problems.

Accordingly, various so-called "dry processes" have been suggested toimprove the process from an environmental viewpoint, as well as toreduce the relative cost of the etching. Furthermore, these "dryprocesses" have the potential advantage of greater process control andhigher aspect ratio images.

Such "dry processes" generally involve passing a gas through a containerand creating a plasma in this gas. The species in this gas are then usedto etch a substrate placed in the chamber or container. Typical examplesof such "dry processes" are plasma etching, sputter etching, andreactive ion etching.

Reactive ion etching provides well-defined, vertically etched sidewalls.A particular reactive ion etching process is disclosed, for example, inU.S. Pat. 4,283,249 to Ephrath, disclosure of which is incorporatedherein by reference.

One problem associated with "dry processing" techniques is providing apatternable material which is sensitive to imaging radiation while, atthe same time, being sufficiently resistant to the dry etchingenvironment. In many instances, resistance to the dry etching, such asto the plasma etching active species, results in erosion of the maskmaterial and the loss of resolution that had been generated by thelithographic exposure to the imaging radiation.

This is true for both positive organic resist materials and negativeorganic resist materials. A positive resist material is one which onexposure to imaging radiation is capable of being rendered soluble in asolvent in which the unexposed resist is not soluble. A negative resistmaterial is one which is capable of polymerizing and/or insolubilizingupon exposure to imaging radiation.

One type of positive photosensitive material is based uponphenol-formaldehyde novolak polymers. A particular example of such isShipley AZ1350 which is a m-cresol formaldehyde novolak polymercomposition. Such is a positive resist composition and includes thereina diazoketone such as 2-diazo-1-naphthol-5-sulphonic acid ester. In sucha composition the diazoketone, during the photochemical reaction, isconverted to a carboxylic acid. This, in turn, renders the exposedresist film readily soluble in weakly alkali aqueous developer solvents.The composition usually contains about 15%, or so, by weight of thediazoketone compound.

A discussion of various photoresist materials can be found, forinstance, in the Journal of the Electrochemical Society, Vol. 125, No.3, March 1980, Deckert, et al., "Microlithography-Key to Solid-StateFabrication", pp. 45C-56C, disclosure of which is incorporated herein byreference.

In addition, certain siloxanes have been suggested as reactive ion etchbarriers. For instance, see Fried, et al., IBM, Journal ResearchDevelopment, Vol. 26, No. 8, pp. 362-371. Also, certain siloxanes havebeen suggested as e-beam sensitive resists. For instance, see Roberts,Journal of Electrochemical Society, Vol. 120, p. 1716, 1973; Roberts,Phillips Technical Review, Vol. 35, pp. 41-52, 1975; and Gazard, et al.,Applied Polymer Symposium, No. 23, pp. 106-107, 1974.

Moreover, there have been suggestions that certain siloxanes, whenimaged with electron beam (see Hatzakis, et al., Processing MicrocircuitEngineering (Lausanne), p. 396, September 1981); and deep U.V. at about2537 Angstrom (see Shaw, et al., SPE Photopolymer Conference, November1982) act as an etch mask for an underlying polymer layer in an oxygenplasma.

U.S. Pat. No. 4,603,195 to Babich, et al. discloses materials which areresistant to dry-processing techniques and especially to reactive ionetching in oxygen plasma while, at the same time, capable of providinghigh resolution images. The compositions disclosed therein are obtainedby interreacting a quinone diazo compound and an organosilicon compound.

In addition, examples of some dry-developable resists are provided inU.S. Pat. Nos. 4,426,247 to Tamamura, et al.; 4,433,044 to Meyer, etal.; 4,357,369 to Kilichowski, et al.; 4,430,153 to Gleason, et al.;4,307,178 to Kaplan, et al.; 4,389,482 to Bargon, et al.; and 4,396,704to Taylor. In addition, German patent application OS32 15082 (Englishlanguage counterpart British patent application 2097143) suggests aprocess for obtaining negative tone plasma resist images. Such isconcerned with a process involving entrapment of a silicon-containingmonomer into a host film at the time of exposure to radiation andrequires a processing step to expel the unincorporated silicon monomerfrom the film before plasma developing of the relief image.

A more recent example of a plasma developable resist is described inU.S. Pat. No. 4,552,833 in which a method is provided for obtaining aresist which is stated to be radiation sensitive and oxygen plasmadevelopable. Such process involves coating a substrate with a film of apolymer that contains a masked reactive functionality, imagewiseexposing the film to radiation under conditions that cause unmasking ofthe reactive functionality in the exposed regions of the film, treatingthe exposed film with a reactive organometallic reagent, and thendeveloping the relief image by treatment with an oxygen plasma. Thespecific organometallic reagents described therein are trimethylstannylchloride, hexamethyldisilazane, and trimethylsilyl chloride.

In addition, a method of obtaining a two-layer resist by top imaging asingle layer resist is described in U.S. patent application Ser. No.679,527 (FI9-84046, assigned to the assignee of the present application)which employs a monofunctional organometallic reagent.

Moreover, U.S. Pat. No. 4,782,008 (assigned to the assignee of thepresent application) discloses oxygen plasma resistant materialsobtained by reacting a polymeric material with a multifunctionalorganometallic material. The organometallic material contains at leasttwo functional groups which are reacted with reactive groups of thepolymeric material. The polymeric material contains reactive hydroxylgroups and/or reactive hydroxyl functional precursor groups.

The disclosures of the above two U.S. patent applications areincorporated herein by reference.

A further disclosure of photosensitive compositions containingorganosilicon compounds can be found in U.S. Pat. No. 4,693,960.

U.S. Pat. No. 4,481,279 describes a dry developable radiation sensitivecomposition based upon polymeric materials containing unsaturatedhydrocarbon bonds (e.g.--polybutadiene, epoxy-containing polymers andcyclolinear polymers) and certain organosilicon compounds which upone-beam irradiation form a reaction product in the exposed areas. Thereaction product is intended to be removed by oxygen plasma therebyproviding a positive tone pattern.

Report RJ 4834 by McDonald et al. is of general interest concerningnegative tone oxygen plasma developable resist based upon thephotogeneration of a reactive functionality within the resist film whichreacts with an organometallic reagent.

Moreover, photopolymerizable compositions that contain an epoxy polymerand various radiation sensitive onium salts have been suggested. Forinstance, see U.S. Pat. Nos. 4,069,055; 4,175,972; 4,572,890; 4,593,052;and 4,624,912.

SUMMARY OF INVENTION

The present invention provides a resist composition that, upon exposureto optical radiation and especially to U.V. wavelengths emitted bymercury vapor lamps, especially 436, 365, 303, 337 and 240 nanometersand deep UV, e.g. below about 240 nanometers, creates a latent imagewhich when can be crosslinked in the exposed areas such as when heatedto provide a negative image. The composition, upon crosslinking, isresistant to dry-processing techniques and especially to reactive ionetching in oxygen plasma. The compositions of the present invention arealso thermally stable (e.g.--up to temperatures of about 380° C.) Inaddition, the compositions of the present invention exhibit goodadhesion to a variety of substrates.

The present invention is concerned with a composition that contains inadmixture:

a polymeric epoxide material containing glycido groups;

a di or polyfunctional organosilicon material, and an onium salt in anamount effective to initiate crosslinking of said polymeric epoxidematerial with said organosilicon.

The onium salt is present in amounts to increase the sensitivity of thecomposition to, for instance, deep U.V. irradiation.

The present invention is also concerned with a process for providing animage which includes providing on a substrate a layer of theorganosilicon and polymeric epoxide compositions of the type disclosedabove, imagewise selectively exposing the layer to a source of energy ina desired pattern creating exposed and unexposed regions; causing theorganosilicon material to crosslink with said polymeric epoxide materialin the exposed regions; vaporizing the unexposed regions; and thenexposing the reactive ions to remove residual material in the unexposedregions.

BEST AND VARIOUS MODES FOR CARRYING OUT INVENTION

The compositions of the present invention contain a polymeric epoxidematerial containing glycido groups.

Typical examples of epoxy polymers include the epoxidized novolakpolymers and the polyepoxides from halo-epoxy alkanes such asepichlorohydrin and a polynuclear dihydric phenol such as bisphenol A.Mixtures of epoxides can be used when desired.

The epoxidized novolak polymers are commercially available and can beprepared by known methods by the reaction of a thermoplastic phenolicaldehyde of a phenol with a halo-epoxy alkane. The phenol can be amononuclear or polynuclear phenol. Examples of mononuclear phenols havethe formula: ##STR1## wherein X, Y, and R₅ are hydrocarbons containingno more than about 12 carbon atoms.

Hydrocarbon-substituted phenols having two available positions ortho orpara to a phenolic hydroxy group for aldehyde condensation to providepolymers suitable for the preparation of epoxy novolaks include o- andp-cresols, o- and p-ethyl phenols, o- and p-isopropyl phenols, o- andp-tert-butyl phenols, o- and p-secbutyl phenols, o- and p-amyl phenols,o- and p-octyl phenols, o- and p-nonyl phenols, 2,5-xylenol,3,4-xylenol, 2,5-diethyl phenol, 3,4-diethyl xylenol, 2,5-diisopropylphenol, 4-methyl resorcinol, 4-ethyl resorcinol, 4-isopropyl resorcinol,4-tert-butyl resorcinol, o- and p-benzyl phenol, o- and p-phenethylphenols, o- and p-phenyl phenols, o- and p-tolyl phenols, o- and p-xylylphenols, o- and p-cyclohexyl phenols, o- and p-cyclopentyl phenols,4-phenethyl resorcinol, 4-tolyl resorcinol, and 4-cyclohexyl resorcinol.

Various chloro-substituted phenols which can also be used in thepreparation of phenol-aldehyde resins suitable for the preparation ofthe epoxy novolaks include o- and p-chlorophenols, 2,5-dichloro-phenol,2,3-dichloro-phenol, 3,4-dichloro-phenol, 2-chloro-3-methyl-phenol,2-chloro-5-methyl-phenol, 3-chloro-2-methyl-phenol,5-chloro-2-methyl-phenol, 3-chloro-4-methyl-phenol,4-chloro-3-methyl-phenol, 4-chloro-3-ethyl-phenol,4-chloro-3-isopropyl-phenol, 3-chloro-4-phenyl-phenol,3-chloro-4-chloro-phenyl-phenol, 3,5-dichloro-4-methyl-phenol,3,5-dichloro-5-methyl-phenol, 3,5-dichloro-2-methyl-phenol,2,3-dichloro-5-methyl-phenol, 2,5-dichloro-3-methyl-phenol,3-chloro-4,5-dimethyl-phenol, 4-chloro-3,4-dimethyl-phenol,2-chloro-3,5-dimethyl-phenol, 5-chloro-2,3-dimethyl-phenol,5-chloro-3,5-dimethyl-phenol, 2,3,5-trichloro-phenol,3,4,5-trichloro-phenol, 4-chloro-resorcinol, 4,5-dichloro-resorcinol,4-chloro-5-methyl-resorcinol, 5-chloro-4-methyl-resorcinol.

Typical phenols which have more than two positions ortho or para to aphenolic hydroxy group available for aldehyde condensation and which, bycontrolled aldehyde condensation, can also be used are: phenol,m-cresol, 3,5-xylenol, m-ethyl and m-isopropyl phenols, m,m'-diethyl anddiisopropyl phenols, m-butyl-phenols, m-amyl phenols, m-octyl phenols,m-nonyl phenols, resorcinol, 5-methyl-resorcinol.

Examples of polynuclear difunctional phenols are those having theformula: ##STR2## wherein Ar is an aromatic divalent hydrocarbon such asnaphthylene and, preferably, phenylene; A and A₁ which can be the sameor different are alkyl radicals, preferably having from 1 to 4 carbonatoms, halogen atoms, i.e., fluorine, chlorine, bromine, and iodine, oralkoxy radicals, preferably having from 1 to 4 carbon atoms; x and y areintegers having a value 0 to a maximum value corresponding to the numberof hydrogen atoms on the aromatic radical (Ar) which can be replaced bysubstituents and R₆ is a bond between adjacent carbon atoms as indihydroxydiphenyl or is a divalent radical including, for example:##STR3## and divalent hydrocarbon radicals, such as alkylene alkylidene,cycloaliphatic, e.g., cycloalkylene and cycloalkylidene, halogenated,alkoxy or aryloxy substituted alkylene, alkylidene and cycloaliphaticradicals, as well as alkarylene and aromatic radicals includinghalogenated, alkyl, alkoxy or aryloxy substituted aromatic radicals anda ring fused to an Ar group; or R¹ can be polyalkoxy, or polysiloxy, ortwo or more alkylidene radicals separated by an aromatic ring, atertiary amino group, an ether linkage, a carbonyl group or a sulfurcontaining group such as sulfoxide, and the like.

Examples of specific dihydric polynuclear phenols include, among others,the bis-(hydroxyphenyl)alkanes such as2,2'-bis-(4-hydroxyphenyl)propane, 2,4-dihydroxydiphenylmethane,bis-(2-hydroxyphenyl)methane, bis-(4-hydroxyphenyl)methane,bis(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)methane,1,1'-bis-(4-hydroxyphenol)ethane, 1,2'-bis-(4hydroxyphenyl)ethane,1,1'-bis-(4-hydroxy-2chlorphenyl)ethane,1,1'-bis-(3-methyl-4hydroxyphenyl)ethane,1,3-bis-(3-methyl-4hydroxyphenyl)propane,2,2'-bis-(3-phenyl-4hydroxyphenyl)propane,2,2'-bis-(3-isopropyl-4hydroxyphenyl)propane,2,2'-bis(2-isopropyl-4hydroxyphenyl)pentane,2,2'-bis-(4-hydroxyphenyl)heptane, bis-(4-hydroxyphenyl)phenylmethane,bis-(4-hydroxyphenyl)cyclohexylmethane,1,2'-bis-(4-hydroxyphenyl)-1,2'-bis-(phenyl)propane and2,2'-bis-(4-hydroxyphenyl)-1-phenyl-propane; di(hydroxyphenyl) sulfonessuch as bis-(4-hydroxyphenyl)sulfone, 2,4'-dihydroxydiphenylsulfone,5'-chloro-2,4'-dihydroxydiphenyl sulfone, and5'-chloro-4,4'-dihydroxydiphenyl sulfone; di(hydroxyphenyl)ethers suchas bis-(4-hydroxyphenyl)ether, the 4,4'-, 4,2'-, 2,2'-, 2,3'-,dihydroxydiphenyl ethers, 4,4'-dihydroxy-2,6-dimethyldiphenyl ether,bis-(4-hydroxy-3-isobutylphenyl)ether,bis-(4-hydroxy-3-isopropylphenyl)ether,bis-(4-hydroxy-3-chlorophenyl)ether,bis-(4-hydroxy-3-fluorophenyl)ether, bis-(4-hydroxy-3-bromophenyl)ether,bis-(4-hydroxynaphthyl)ether, bis-(4-hydroxy-3-chloronaphthyl)ether,bis-(2-hydroxydiphenyl)ether, 4,4,-dihydroxy-2,6-dimethoxydiphenylether, and 4,4'-dihydroxy-2,5-diethoxydiphenyl ether.

The preferred dihydric polynuolear phenols are represented by theformula: ##STR4## wherein A and A₁ are as previously defined, x and yhave values from 0 to 4 inclusive and R₆ is a divalent saturatedaliphatic hydrocarbon radical, particularly alkylene and alkylideneradicals having from 1 to 3 carbon atoms, and cycloalkylene radicalshaving up to and including 10 carbon atoms. The most preferred dihydricphenol is bisphenol A, i.e., 2,2'-bis(p-hydroxyphenyl)propane.

As condensing agents, any aldehyde may be used which will condense withthe particular phenol being used, including formaldehyde, acetaldehyde,propionaldehyde, butyraldehyde, heptaldehyde, cyclohexanone, methylcyclohexanone, cyclopentanone, benzaldehyde, and nuclearalkyl-substituted benzaldehydes, such as toluic aldehyde,naphthaldehyde, furfuraldehyde, glyoxal, acrolein, or compounds capableof engendering aldehydes such as para-formaldehyde, hexamethylenetetramine. The aldehydes can also be used in the form of a solution,such as the commercially available formalin. The preferred aldehyde isformaldehyde.

The halo-epoxy alkane can be represented by the formula: ##STR5##wherein X is a halogen atom (e.g., chlorine, bromine, and the like), pis an integer from 1-8, each R₂ individually is hydrogen or alkyl groupof up to 7 carbon atoms; wherein the number of carbon atoms in any epoxyalkyl group totals no more than 10 carbon atoms.

While glycidyl ethers such as derived from epichlorohydrin areparticularly preferred in the practice of this invention, the epoxypolymers containing epoxyalkoxy groups of a greater number of carbonatoms are also suitable. These are prepared by substituting forepichlorohydrin such representative corresponding chlorides or bromidesof monohydroxy epoxyalkanes as 1-chloro-2,3-epoxybutane,1-chloro-3,4-epoxybutane, 2-chloro-3,4-epoxybutane,1-chloro-2-methyl-2,3-epoxypropane, 1-bromo-2,3-epoxypentane,2-chloromethyl-1,2-epoxybutane, 1-bromo-4-methyl-3,4-epoxypentane,1-bromo-4-ethyl-2,3-epoxypentane, 4-chloro-2-methyl-2,3-epoxypentane,1-chloro-2,3-epoxyoctane, 1-chloro-2-methyl-2,3-epoxyoctane, or1-chloro-2,3-epoxydecane. Although it is possible to usehaloepoxyalkanes having a greater number of carbon atoms than indicatedabove, there is generally no advantage in using those having a total ofmore than 10 carbon atoms.

The preferred epoxidized novolacs employed in the present invention arerepresented by the following average formulae: ##STR6## Polyepoxidesrepresented by formula 1 are commercially available under the tradedesignation EPI-REZ SU8^(R), and those represented by formula 2 areavailable under the trade designation EPI-REZ SU6^(R). EPI-REZ SU8^(R)is supplied as a 74% weight solution of the epoxy in methyl isobutylketone.

In addition, the polyepoxides of halo epoxy alkane of the type discussedabove and a polynuclear dihydric phenol of the type above can beemployed. The preferred polyepoxides of this class being thepolyepoxides of epichlorohydrin and bisphenol A, i.e.,2,2-bis(p-hydroxyphenyl)propane.

The di- and polyfunctional organosilicon materials employed pursuant tothe present invention include at least two functional groups capable ofcrosslinking glycidyl groups of the epoxide material.

The organosilicon material includes reactive epoxy group or reactivehydrogen group such as NH₂, OH and SH. Examples of suitableorganosilicon materials include those represented by the formulae:##STR7## X is a reactive epoxy group or reactive hydrogen group such asNH₂, OH and SH.

The R radicals in the above formulae 3 to 11 are well-known and aretypified by radicals usually associated with silicon-bonded organicgroups and silicon-bonded hydrogen groups. Each R radical in the aboveformulae 3 and 4 is individually selected from the group of hydrogen,monovalent hydrocarbon radicals, halogenated monovalent hydrocarbonradicals, epoxy groups, mercapto radicals, and cyanoalkyl radicals.Thus, the radical R may be alkyl, such as methyl, ethyl, propyl, butyl,octyl; aryl radicals such as phenyl, tolyl, xylyl, napthyl radicals;aralkyl radicals such as benzyl, phenylethyl radicals; olefinicallyunsaturated monovalent hydrocarbon radicals such as vinyl, allyl,cyclohexenyl radicals; cycloalkyl radicals such as cyclohexyl,cycloheptyl; halogenated monovalent hydrocarbon radicals such asdichloropropyl, 1,1,1-trifluoropropyl, chlorophenyl, dibromophenyl,chloromethyl, and other such radicals; cyanoalkyl radicals such ascyanoethyl, and cyanopropyl. Preferably, the radicals represented by Rhave less than eight carbon atoms and in particular it is preferred thatR be methyl, ethyl, or phenyl.

The "a" in formula 4 is an integer of 1-5 and preferably 3.

The "b" in formula 5 is an integer of 1-3.

The "d" in formula 6 is an integer of 0-3.

The "e" in formula 9 is an integer of 1 to about 10.

Examples of organosilicon materials suitable for use in the presentinvention are bis(hydroxydimethylsilyl)-benzene;bis(glycidoxypropyl)-tetramethyldisiloxane,glycidoxypropyltrimethoxy-silane glycidoxyphenyl trimethoxysilane,glycidoxy methyl silanes, tetramethyl siloxanediol;dimethylsiloxanediol; bis(hydroxypropyl)tetramethyldisiloxane, andcarboxypropyl tetramethyldisiloxane.

The amount of organosilicon material is usually about 5% to about 50%and preferably about 10% to about 25% per mole of polymeric epoxymaterial.

The compositions of the present invention also contain a radiationsensitive onium salt. The radiation sensitive onium salt is present inamounts effective to increase the radiation sensitivity of thecomposition and usually about 0.5% to about 20% by weight, andpreferably about 1% to about 10% by weight based upon the weight of thepolymeric epoxide material.

Examples of suitable onium salts include aromatic onium salts of GroupIV elements discussed in U.S. Pat. No. 4,175,972, disclosure of which isincorporated herein by reference, and aromatic onium salts of Group Vaelements discussed in U.S. Pat. No. 4,069,055, disclosure of which isincorporated herein by reference.

Aromatic Group IVa onium salts include those represented by the formula:

    [(R).sub.a (R.sup.1).sub.b (R.sup.2).sub.c X].sub.d.sup.+ ]MQ.sub.e ]-.sup.(e-f)

where R is a monovalent aromatic organic radical, R¹ is a monovalentorganic aliphatic radial selected from alkyl, cycloalkyl and substitutedalkyl, R² is a polyvalent organic radical forming a heterocyclic orfused ring structure selected from aliphatic radicals and aromaticradicals, X is a Group IVa element selected from sulfur, selenium, andtellurium, M is a metal or metalloid, Q is a halogen radical, a is awhole number equal to 0 to 3 inclusive, b is a whole number equal to 0to 2 inclusive, c is a whole number equal to 0 or 1, where the sum ofa+b+c is a value equal to 3 or the valence of X,

    d=e-f

f=valence of M and is an integer equal to from 2 to 7 inclusive, e is >fand is an integer having a value up to 8.

Radicals included by R are, for example, C.sub.(6-13) aromatichydrocarbon radicals such as phenyl, tolyl, naphthyl, anthryl, and suchradicals substituted with up to 1 to 4 monovalent radicals such asC.sub.(1-8) alkoxy, C.sub.(1-8) alkyl, nitro, chloro, and hydroxy;arylacyl radicals such as benzyl and phenylacyl; aromatic heterocyclicradicals such as pyridyl and furfuryl. R¹ radicals include C.sub.(1-8)alkyl such as methyl and ethyl, substituted alkyl such as --C₂ H₄ OCH₃,--CH₂ COOC₂ H₅, --CH₂ COCH₃, etc. R² radicals include such structuresas: ##STR8## Complex anions included by MQ_(e) ⁻(e-f) of Formula I are,for example, BR₄ ⁻, PF₆ ⁻, SbF₆ ⁻, FeCl₄ ⁻, SnCl₆ ⁻, SbCl₆ ⁻, BiCl₅ -,AlF₆ ⁻³, GaCl₄ ⁻, InF₄ ⁻, TiF₆ ⁻, ZrF₆ ⁻, etc., where M is a transitionmetal such as Sb, Fe, Sn, Bi, Al, Ga, In, Ti, Zr, Sc, V, CR, Mn, Cs,rare earth elements such as the lanthanides, for example, Ce, Pr, Nd,etc., actinides, such as Th, Pa, U, Np, etc. and metalloids such as B,P, and As.

Group VIa onium salts included by Formula I are, for example: ##STR9##Aromatic group Va onium salts include those represented by the formula:##STR10## where R is a monovalent aromatic organic radical selected fromcarbocyclic radicals and heterocyclic radicals, R¹ is a monovalentorganic aliphatic radical selected from alkyl, alkoxy, cycloalkyl andsubstituted derivatives thereof, R² is a polyvalent organic radicalforming an aromatic heterocylic or fused ring structure with X¹, X¹ is aGroup Va element selected from N, P, As, Sb, and Bi, M is a metal ormetalloid, Q is a halogen radical, a is a whole number equal to 0 to 4inclusive, b is a whole number equal to 0 to 2 inclusive, c is a wholenumber equal to 0 to 2 inclusive, and the sum of a+b+c is a value equalto 4 or the valence of X¹,

    d=e-f

f=valence of M and is an integer equal to from 2 to 7 inclusive, e is >fand is an integer having a value up to 8.

Radicals included by R are, for example, C.sub.(6-13) aromatichydrocarbon radicals such as phenyl, tolyl, naphthyl, anthryl and suchradicals substituted with up to 1 to 4 monovalent radicals such asC.sub.(1-8) alkoxy, C.sub.(1-8) alkyl, nitro, chloro, and hydroxy;arylacyl radicals such as phenylacyl; arylalkyl radicals such as phenylethyl; aromatic heterocylic radicals such as pyridyl and furfuryl; R¹radicals include C.sub.(1-8) alkyl, C.sub.(3-8) cycloalkyl, substitutedalkyl such as haloalkyl, for example, chloroethyl; alkoxy such as OCH₂C₆ H₅ and OCH₃ ; alkoxyalkyl such as --C₂ H₄ OCH₃ ; alkylacyl such as--CH₂ COOC₂ H₅ ; ketoalkyl such as --CH₂ COCH₃.

Radicals included by R² are, for example: ##STR11## where Q' is selectedfrom 0, CH₂, N, R, and S; Z is selected from --O--, --S-- and ##STR12##and R' is a monovalent radical selected from hydrogen and hydrocarbon.Complex anions included by MQ_(e) ⁻(e-f) are, for example, BF₄ ⁻, PF₆ ⁻,AsF₆ ⁻, FeCl₄ ⁼, SnCl₆ ⁻, SbCl₆ ⁻, BiCl₅ ⁼, where M is more particularlya transition metal such as Sb, Fe, Sn, Bi, Al, Ga, In, Ti, Zr, Sc, V,Cr, Mn, and Co; rare earth elements such as the lanthanides, forexample, Ce, Pr, and Nd; actinides such as Th, Pa, U, and Np; andmetalloids such as B, P, and As.

In addition, it is noted that the compounds of the present invention canbe admixed with conventional additives such as fillers, plasticizers,and diluents.

Examples of some inert diluents are diglyme, methyl isobutyl ketone,propylene glycol, methyl ether acetate, and ethyl acetate.

When used as a lithographic material, the compositions of the presentinvention are applied to a desired substrate to provide films, generallyabout 1500 angstroms to about 1 mil thick, and preferably about 2000 toabout 3000 angstroms, such as by spraying, spinning, dipping, or anyother known means of application of coating. Some suitable substratesinclude those used in the fabrication of semiconductor devices orintegrated circuits which include wafers or chips overcoated with oxidesand nitrides (silicon oxide and/or silicon nitride for diffusion masksand passivation) and/or metals normally employed in the metallizationsteps for forming contacts and conductor patterns on the semiconductorchip. The compositions can be coated on a variety of substrates withoutrequiring an adhesion primer layer.

In addition, the materials of the present invention can be used inconjunction with those substrates employed as chip carriers andincluding ceramic substrates and, especially, multilayer ceramicdevices. Also included are dielectric substrates which can bethermoplastic and/or thermosetting polymers. Typical thermosettingpolymeric materials include epoxy, phenolic-based materials, polyamides,and polyimides. The dielectric materials may be molded articles of thepolymeric materials containing fillers and/or reinforcing agents such asglass-filled epoxy or phenolic-based materials. Examples of somephenolic-type materials include copolymers of phenol, resorcinol, andcresol. Examples of some suitable thermoplastic polymeric materialsinclude polyolefins such as polypropylene; polysulfones; polycarbonates;nitrile rubber; and ABS polymers.

The compositions of the present invention are exposed to actinicradiation, preferably to deep U.V. of wavelength of about 230-290 andpreferably 240 nanometers at energy levels of about 10 to about 15millejoules or e-beam at 10 to about 100 kilovolts. Prior to exposure,prebake of the composition is not required.

The exposure to the radiation creates a latent image which whensubjected to elevated temperatures, results in crosslinking in thoseregions which were exposed to the radiation since the compositions areof the negative resist type. The heating is generally carried at about80° to about 120° C., typically about 90° C. for about 0.1 to about 25minutes, typically about 10 to about 15 minutes. This heating results incrosslinking of the silicon material with the epoxide material in theexposed areas thereby incorporating the silicon component of the mixturechemically. At the same time, the heating causes vaporation of materialin the unirradiated areas of mixture resulting in thickness less in suchunirradiated areas thereby creating a relief pattern. A typicalthickness loss is about 2 to about 3000 angstroms depending upon theextent of the exposure.

The film is then subjected to an oxygen plasma which removes the organicmaterial in the unexposed areas at a rate at least ten times faster thanthat in the exposed areas. The exposed regions erode at a low rate sinceit contains silicon in an amount sufficient to create a layer of siliconoxide. Typical plasma parameters about are 10 mTorr O₂ pressure, about0.15 w/cm² for about 5 minutes.

The following non-limiting examples are presented to further illustratethe present invention.

EXAMPLE 1

A mixture of a polymeric epoxide and an organosilicon material isobtained by admixing about 33.5 parts by weight of a 74% by weightsolution of EPI-REZ SU8^(R) in methyl isobutyl ketone; about 87.6 partsby weight of diglyme, about 12 parts by weight ofbis(hydroxydimethylsilyl) benzene and about 1 part by weight oftriphenyl sulfonium hexafluoride antimonate. The solids content of themixture includes about 8.1% by weight of silicon. The composition iscoated onto a silicon substrate at a thickness of about 5000 angstromsto about 10,000 angstroms and exposed imagewise in a predeterminedpattern to deep ultraviolet light irradiation at about 230-290nanometers at about 10-15 millejoules/cm². The coating is then postbakedby placing the coated substrate on a hot plate at about 90° C. for about10-15 minutes resulting in a loss in thickness of the unexposed regionsof about 10-20% due to vaporization of the organosilicon material. Thelayer is then subjected to oxygen plasma at about 10 mTorr O₂, and about0.15 w/cm². This results in complete removal of the residual material inthe unexposed regions while leaving about 80% of the thickness of theexposed layer.

The latter plasma process is optional for the described formulation.

What is claimed is:
 1. A dry developable photoresist compositionconsisting essentially of in admixture:a polymeric epoxide materialcontaining glycidyl groups; an organosilicon material represented by thefollowing formula: ##STR13## wherein X is selected from the groupconsisting of reactive epoxy group and a group containing reactivehydrogen; each R is individually selected from the group consisting ofhydrogen, monovalent hydrocarbon radicals, halogenated monovalenthydrocarbon radicals, epoxy groups, mercapto radicals and cyanoalkylradicals; and an onium salt in an amount effective to initiatecrosslinking of said polymeric epoxide material with said organosilicon.2. The composition of claim 1 wherein the amount of the organosiliconcompound is about 20 to about 50% mole of the composition.
 3. Thecomposition of claim 1 wherein said polymeric epoxide material isselected from the group of epoxidized novolacs having the averageformulae: ##STR14##
 4. The composition of claim 1 wherein said polymericepoxide has the average formula: ##STR15##
 5. The composition of claim 1wherein said polymeric epoxide has at least 6 terminal epoxy groups. 6.The composition of claim 1 wherein said polymeric epoxide has at least 8terminal epoxy groups.
 7. The composition of claim 1 wherein said oniumsalt is an aromatic salt of a Group IVa element.
 8. The composition ofclaim 1 wherein said onium salt is triphenyl sulfonium hexafluorideantimonate.
 9. The composition of claim 1 wherein the amount of saidonium salt is about 3% to about 10% by weight based upon the weight ofthe polymeric epoxide material.
 10. The composition of claim 1 whichfurther contains a diluent.
 11. The composition of claim 1 wherein saidorganosilicon material is bis (hydroxydimethylsilyl) benzene.
 12. Thecomposition of claim 1 wherein X is OH.
 13. A dry developablephotoresist composition comprising in admixture:a polymeric epoxidehaving at least 6 terminal epoxy groups; an organosilicon materialrepresented by the following formula: ##STR16## wherein X is selectedfrom the group consisting of reactive epoxy group and a group containingreactive hydrogen; each R is individually selected from the groupconsisting of hydrogen, monovalent hydrocarbon radicals, halogenatedmonovalent hydrocarbon radicals, epoxy groups, mercapto radicals andcyanoalkyl radicals; and an onium salt in an amount effective toinitiate crosslinking of said polymeric epoxide material with saidorganosilicon.
 14. The composition of claim 13 wherein the amount of theorganosilicon compound is about 10 to about 25% per of epoxide.
 15. Thecomposition of claim 13 wherein said polymeric epoxide material isselected from the group of epoxidized novolacs having the averageformulae: ##STR17##
 16. The composition of claim 13 wherein saidpolymeric epoxide has the average formula: ##STR18##
 17. The compositionof claim 13 wherein said polymeric epoxide has at least 8 terminal epoxygroups.
 18. The composition of claim 13 wherein said onium salt is anaromatic salt of a Group IVa element.
 19. The composition of claim 13wherein said onium salt is triphenyl sulfonium hexafluoride antimonate.20. The composition of claim 13 wherein the amount of said onium salt isabout 3% to about 10% by weight based upon the weight of the polymericepoxide material.
 21. The composition of claim 13 wherein saidorganosilicon material is bis (hydroxydimethylsilyl) benzene.
 22. Thecomposition of claim 13 wherein X is OH.
 23. The composition of claim 13wherein X is selected from the group of NH₂, OH and SH.